Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/30-21 | 255/25-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.02 (686.4) | 26.02 (660.9) | -1 (-25.5) -3.7% |
| Width inches (mm) | 10.04 (255) | 10.04 (255) | 0 (0) 0% |
| Circum. inches (mm) | 84.9 (2156.39) | 81.74 (2076.28) | -3.15 (-80.11) -3.7% |
| Sidewall Height inches (mm) | 3.01 (76.5) | 2.51 (63.75) | -0.5 (-12.75) -16.7% |
| Revolutions per mile (km) | 746.31 (463.74) | 775.11 (481.63) | 28.8 (17.89) 3.9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.26 mph (30.99 km/h) |
| 25 mph (40.23 km/h) | 24.07 mph (38.74 km/h) |
| 30 mph (48.28 km/h) | 28.89 mph (46.49 km/h) |
| 35 mph (56.33 km/h) | 33.7 mph (54.23 km/h) |
| 40 mph (64.37 km/h) | 38.51 mph (61.98 km/h) |
| 45 mph (72.42 km/h) | 43.33 mph (69.73 km/h) |
| 50 mph (80.47 km/h) | 48.14 mph (77.48 km/h) |
| 55 mph (88.51 km/h) | 52.96 mph (85.23 km/h) |
| 60 mph (96.56 km/h) | 57.77 mph (92.97 km/h) |
| 65 mph (104.61 km/h) | 62.59 mph (100.72 km/h) |
| 70 mph (112.65 km/h) | 67.4 mph (108.47 km/h) |
| 75 mph (120.7 km/h) | 72.21 mph (116.22 km/h) |
| 80 mph (128.75 km/h) | 77.03 mph (123.96 km/h) |
| 85 mph (136.79 km/h) | 81.84 mph (131.71 km/h) |
| 90 mph (144.84 km/h) | 86.66 mph (139.46 km/h) |
| 95 mph (152.89 km/h) | 91.47 mph (147.21 km/h) |
| 100 mph (160.93 km/h) | 96.28 mph (154.96 km/h) |
| 2.35 | 2.73 | 2.94 | 3.07 | 3.21 | 3.31 | 3.42 | 3.55 | 3.73 | 3.91 | 4.11 | 4.27 | 4.56 | 4.88 | 5.13 | 5.29 | 5.38 | 5.71 | 6.17 | 7.17 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1973 | 2291 | 2468 | 2577 | 2694 | 2778 | 2871 | 2980 | 3131 | 3282 | 3450 | 3584 | 3828 | 4096 | 4306 | 4440 | 4516 | 4793 | 5179 | 6018 |
Better Fuel Economy Factory Ratios Increased Power
